1. Field of the Invention
The invention relates to a method and apparatus for resolving benign paroxysmal positional vertigo (BPPV).
2. Background
BPPV
BPPV is classically used to refer to vertigo caused by loosened otoconia crystals in the posterior semicircular canal, the most common inner ear semicircular canal effected by loosened otoconia. To those trained in the art, given the current understanding of the pathophysiology of BPPV, the definition of BPPV is positional vertigo caused by loosened crystals in any of the membranous semicircular canals moving in response to gravity. This more generalized definition is the one used in this application. I will refer to classic posterior semicircular canal positional vertigo as posterior BPPV or PBPPV, horizontal BPPV as HBPPV and superior semicircular canal BPPV as SBPPV.
Pathophysiology of BPPV
BPPV is caused by 1) naturally occurring calcium carbonate crystals becoming dislodged and falling from their normally occurring position on the utricular macula and 2) a significant number of the crystals coming to be located in a membranous semicircular canal. When the patient places the head such that a particular semicircular canal is vertical, the loosened crystal(s) causes motion of the rotation sensor causing the patient to sense vertigo. These symptoms typically resolve when the loosened crystal dissolves in the surrounding endolymphatic fluid. If the loosened crystals can be moved out of the affected membranous SCC then the patient symptoms are markedly decreased or resolved.
Incidence of BPPV
90 million Americans (42% of the population) will experience vertigo some time in their life. Approximately three million people of the 250 million people in the US suffer some vertigo each year. Vertigo is the most common physician visit diagnosis in patients over 65 years of age. Seventeen percent of patients who have dizziness have benign paroxysmal positional vertigo (BPPV). According to Fife1, 91% of the BPPV patients were thought to have involvement of the posterior semicircular canal, 6% involvement of the horizontal canal (7.8% according to Takegoshi2), and 3% involvement of the superior (or anterior) semicircular canal. This application is directed to a new method and apparatus for the diagnosis and treatment of posterior BPPV and the treatment of benign paroxysmal positional vertigo in the horizontal and superior semicircular canals.
Types of BPPV
Posterior BPPV
PBBPV""s hallmark is vertigo when the patient moves into the affected ear downward position. The patient may also have symptoms of dizziness with looking up, or looking down. The diagnosis is clinically confirmed by placing the patient in the affected ear down position and watching a characteristic rotary motion of the eyes. Although some cases of BPPV follow head trauma, most cases have spontaneous onset of unknown origin. The natural history of positional vertigo is one of spontaneous remission, typically over 6 weeks. Recurrence is common and can last from weeks to months.
One ear is usually involved but reports of up to 15% of bilateral ear involvement have been made.
PBPPV is caused when a significant number of the loosened crystals come to be located within the posterior semicircular canal.
PBPPV Treatments
In 1980 Brandt Daroff3 described a sequence of maneuvers in which the patient sat on the edge of a bed/surface and lay down laterally with the head touching the surface. After the symptoms resolved he sat up and lay down on the opposite side. This was done every three hours while awake and terminated after two symptom-free days. This maneuver was thought to free the otolithic debris which was attached to the cupula of the posterior semicircular canal ampulla.
Semont4 described what he called a Liberatory maneuver in which the patient was rapidly moved from a sitting position to the provoking position and kept in that position for 2-3 minutes. The patient was then rapidly brought up through the sitting position to lie on the contralateral side with the head turned downward 45 degrees. The therapist maintained the alignment of the neck and head on the body. The patient stayed in this second position for 5 minutes. In this second position the vertigo reappears and resolves. After the vertigo resolved the patient was slowly returned to a seated position and remained vertical for 48 hours thereafter. This technique was thought to work by causing the debris within the posterior semicircular canal to fall out of the canal.
Norre5,6,7 described the use of vestibular rehabilitation maneuvers for the treatment of BPPV. Some support for this use of this compared to the liberatory and Epley canalith repositioning maneuvers has been expressed.
Epley8,9 studied and refined Semont""s Liberatory maneuver4. Epley""s maneuver is now thought to be the most effective technique for moving the crystals out of the posterior membranous SCC (posterior canalith repositioning maneuver).
This maneuver is defined by Epley8,9 as being made up of 6 positions: Start, and Positions 1, 2, 3, 4, and 5. The start position is the patient seated upright in an examination chair or on a table looking forward with the operator behind the patient and a mastoid oscillator applied to the effected ear behind the ear (ipsilateral mastoid area). In position 1, the patient is lying supine with the neck extended 20 degrees and the head turned 45 degrees toward the effected ear downward position. In position 1, while the neck continues to be extended 20 degrees, the head is turned 90 degrees toward the unaffected ear i.e. 45 degrees from vertical in the direction of the unaffected ear into position 2. To go from position 2 to position 3, the neck is kept extended 20 degrees, the patient rolls onto the unaffected ear side of their body and the head is rolled into position 3. In position three, the head (nose) is pointed 135 degrees downward, affected ear upward, from the supine position. Keeping the head (nose) in the 135 degrees downward position, the patient is brought up to a sitting position, position 4. In position 5, the head is turned forward and the chin downward 20 degrees. Each position is held until the induced nystagmus stops (xe2x80x9capproaches terminationxe2x80x9d).
Harvey10 described a modification of Semont""s Liberatory maneuver which is very similar in its positions to that of Epley""s canalith repositioning maneuver.
Katsarkas11 showed a modification of the Epley canalith repositioning maneuver which he developed. In his maneuver, after the Epley position 3, he extends the neck as far as is reasonably possible to allow (he believes) the otoconia to fall into and through the common crus portion of the posterior semicircular canal crystal removal route.
Best PBPPV Treatment Observations
One skilled in the art will recognize that the head maneuver to relieve PBPPV can be done in an large (theoretically infinite) number of positions. That is, this maneuver could be done using the same head movement sequence outlined by the six positions of the posterior CRP maneuver, but it could be done such that instead of Epley positions 1, 2 and 3 being 90 degrees from the previous positions, the maneuver could be divided into five positions each 45 degrees from the position that preceded it and 45 degree from the position that follows it. If resolution of clinical vertigo caused by each position was used as the indicator to proceed to the next position, this theoretical five position maneuver would be as effective in the resolution of BPPV as Epley described in his positions 1, 2, and 3.
In the same way, those skilled in the art will recognize that this rotation of the head could be broken up into many (theoretically an infinite number of) positions. To one skilled in the art, the clinical use of a complex multipositioned maneuver is not clinically possible because of the increased difficulty of correct and consistent positioning when a multipositional maneuver is done manually. This difficulty is increased further for the occasional performer, and markedly more for the less educated and therefore less physiologically understanding occasional performer.
Those skilled in the art recognize that the posterior CRP technique teaches that the Epley positions 1, and 2 are done with the patient""s head extended 20 degrees, the patient""s head is supine and rotated 45 degrees in the effected ear downward position (position one) and rotates toward the unaffected ear downward (into position two) and then into position three with the nose pointed 135 degrees downward from supine (position three).
Theoretically the best sequence of head positions for clearing crystals from the posterior SCC is the position sequence which would cause position two to have the top of the patient""s head directly downward. Positions one and three could be approximately the same as Epley classically described. That is, those skilled in the art will recognize that the greater the patient""s neck is extended (up to 90 degrees) in positions one and two but especially in position two, the greater the chances that the maneuver will effectively clear the symptom-causing crystals from the posterior SCC.
This technique of total patient rotation in the plane of the posterior semicircular canal has been done by Epley8 using a specially build chair and rotation apparatus. Lempert12 performed a similar procedure demonstrating the value of the Epley position one to the Epley position three through an Epley position two in which the patient""s head was pointed directly downward.
Understanding that this head extension greater than 20 degrees and up to 90 degrees makes the maneuver more effective, the current invention discloses devices which cause the head extension up to 110 degrees. Based on this teaching, this invention includes not only the current configuration but devices which cause the neck to be extended greater than or equal to 10 degrees and up to 110 degrees in the Epley positions one and two.
A Clinical Perspective
The posterior canalith repositioning maneuver technique is currently used by medical and paramedical personnel worldwide for the relief of the symptoms of posterior semicircular canal BPPV. The technique, although easy to do and successful after it is learned, is difficult to successfully teach.
The maneuver requires significant experience by the performer to be consistently successful. Attempts to teach the maneuver to patients have been unsuccessful. The present invention accurately, consistently and inexpensively provides the user visual feedback as to his head position at any given moment, and provides a path for the user to follow to move his head correctly through the series of positions to accomplish the canalith repositioning maneuver.
Horizontal BPPV
Horizontal BPPV (HBPPV) was first recognized by McClure13 who reported 7 cases with brief episodes of positional vertigo associated with horizontal direction changing positional vertigo. Subsequent studies have reported several variation in the type of nystagmus produced by horizontal canal BPPV, including geotropic and ageotropic direction changing positional nystagmus.
The clinical characteristics are 1) brief episodes of positional vertigo and 2) paroxysmal bursts of horizontal positional nystagmus and 3) lack of any other identifiable central nervous system disorder.
Geotropic horizontal direction changing paroxysmal nystagmus has been found in HBPPV in 90% by Nuti14, and 73% by Takegoshi2 and 84% by Fife1. Takegoshi2 reported finding BPPV in both the posterior and horizontal semicircular canals. Nuti14, McClure13 and Herdman15 reported finding horizontal canal BPPV after canalith repositioning maneuver for relief of PBPPV.
HBPPV Treatments
Fife1 described three maneuver techniques for treating HBPPV.
The first maneuver was a three-quarter contralateral roll in which the patient""s head was moved in 90 degree increments away from the side with the most intense nystagmus to achieve a 270 degree turn. This maneuver was largely unsuccessful in the small number of patient upon whom it was used.
The second maneuver was a single full contralateral roll. This second maneuver was similar to the first, except that the head was rotated the entire 360 degree turn from supine face up to supine face up, again turning toward the presumably unaffected ear.
The third maneuver was the iterative full contralateral roll. These exercises were performed once or twice in the clinic and the patient was encouraged to continue these at home for 7 days or until the symptoms subsided. The head was maintained in 30 degree flexion throughout the maneuver.
Epley describes treating horizontal canal HBPPV with a 360 degree xe2x80x9cbarrel rollxe2x80x9d away from the involved ear, keeping the horizontal canal in the earth vertical plane. To avoid dumping particles from the utricle back into the horizontal canal at the end of the procedure, the patient was returned to upright without first moving to the straight supine position. Epley notes that in the less agile patients, success can still be obtained by turning the head only 135 degrees from supine, opposite the involved ear.
Superior BPPV Treatments
Treatment maneuver to remove loosened otoconia from the superior (or anterior) semicircular canal has only been described by one author. Epley notes xe2x80x9cthe anterior canals can usually be cleared of canaliths by using the same positioning sequence as for centralateral posterior canalithsxe2x80x9d.
BPPV Diagnostic
The classic clinical description of PBPPV includes rotary nystagmus in the effected ear down Dix-Hallpike position. Because head placement is difficult to describe in a manner that a non medical person could accurately and consistently perform, and because the accuracy of which posterior semicircular canal is not detected perfectly by the questionnaire, there will be described a device which will guide the user""s head into the right Dix-Hallpike and the left Dix-Hallpike positions. While in these positions the user can detect and understand which ear down causes the greatest amount of vertigo symptoms and hence which (right or left) post SCC is effected by the loosened otoconia. The ear which is effected is the ear which is initially placed downward in the treatment maneuver. That is, the treatment maneuver is effected-side-specific.
Based on this information and the fact that the studies of BPPV, response to head maneuvers all start from the knowledge of which ear is effected. A device to guide the user""s head into each of the two Dix-Hallpike positions is conceived and described herein. There are no prior art devices to this applicant""s knowledge which guide the user""s head into the Dix-Hallpike positions for diagnostic purposes.
Prior Art
A device for sale by Medical Surgical Innovations 1 Ocean Drive, Jupiter, Fla. consists of a combination of head band and skull vibrator.
The headband is worn around the head like a tennis sweat band. It is made from colorful neoprene and is of adjustable tension by varying the tightness of the attaching VELCRO(copyright) strip. Attached to the VELCRO(copyright) head band at the lateral side of the forehead on both sides in a plane parallel to the posterior semicircular canal on the opposite side is a small clear tube filled with water and containing a small amount of sand. This tube is intended to give the medical/paramedical person performing the maneuver for the patient, a visual feedback technique to see that the position sequence into which they are positioning the patient will cause the sand suspended in water to move around the tube of water in the same way that the loosened crystalline otoconia are being moved around and out of the posterior membranous semicircular canal. This device is intended for use by medical/paramedical personnel to judge the success of the positioning sequence that they are performing for the user.
The head band is used to hold a vibrator against the skull behind the effected ear for several minutes before and during the PCRP.
The skull vibrator is a small hand held, battery operated vibrator within a smooth plastic case. This vibrator was held against the mastoid surface behind the ear which was thought to be causing the BPPV symptoms.
Two authors (Epley8, Lempert12) have reported seating the patient in a device and completely rotating the patient in the plane of the posterior semicircular canal (with the capability to rotate the patient in the plane of any of the semicircular canals). These large devices represent the most accurate method of CRP for any of the canals. Ownership and self operation of these devices is certainly not feasible for the vast majority of patient suffering from BPPV.
The application discloses a visual feedback method and apparatus which attaches to a person""s head allowing a user to 1) establish or help establish a) a diagnosis of BPPV and b) determine which ear in PBPPV is involved and 2) to treat the user""s BPPV.
The user device attaches to the user""s head to measure head position and uses any of several embodiments to give the user visual feedback about his head position or series of head positions.
The device is sensitive to different spatial positions for displaying information sufficient to allow the person to see and follow a given path with the person""s head when the device is coupled to the person""s head. As the path is followed by the person""s head, the person""s head is moved through the diagnostic Hallpike positions and the relief head positions of the Epley maneuver.
It has been determined that movement of the user""s head into the diagnostic Hallpike positions and through the relief head positions sequences of the Epley maneuver is a complex maneuver. The times during which the goggle device will be used is further complicated by the user being dizzy with the associated loss of orientation in space. Additionally the diagnostic Hallpike position and the first head position of the relief Epley maneuvers puts the user""s head in the position that maximally stimulates his/her vertigo. Because of these factors there is a desire for an assistant to the user.
Thus, there is provided an assistant apparatus attached to the user apparatus which allows an assistant to monitor the process of the user and to instruct the user in the process.
The preferred embodiment of the assistant apparatus comprises a hollow ball or chamber member attached to the user apparatus with a liquid located in the ball sufficient to form a bubble which allows the assistant to follow a path on the exterior of the ball which corresponds to that seen by the user when the user follows the user path.
This embodiment of the bubble in water assistant apparatus may be coupled to the patient""s head and used by itself by the assistant for the diagnosis and treatment of BPPV without the use of a user feedback apparatus.
In one embodiment of the user apparatus, there is provided a fluid suspended, inner member upon which is formed a numbered series of position bull""s eyes which are connected by a path. This inner member is contained within a clear plastic water tight outer housing which has a sighting device printed upon it. This device is held at a fixed distance from the eye with the appropriate lens to allow the user to focus upon the inner member position bull""s eye. The device is attached to the user""s head in a manner that the outer housing sighting device and an aligned inner ear position bull""s eyes can be seen by the user. The user moves his head such that the outer housing sighting device and inner member""s position bull""s eyes are sequentially aligned. Between each position bull""s eye and the next, the sighting device is kept aligned with the path. Together these provide a pathway for the user to visually track his correct head position through the posterior canalith repositioning maneuver sequence.
The housing-inner member device also may be used for diagnostic purposes.
In another embodiment of the user apparatus the horizontal axis orientation of the buoyancy neutral inner member is provided by an entrapment mechanism between the outer housing and inner member.
Another embodiment employs of the user apparatus employs sand in a liquid contained in a torodial shaped tube for BPPV diagnosis and treatment.
In another embodiment of the user apparatus, a rolling ball located in an outer sphere with a guiding path on the inside of the outer sphere is employed for BPPV treatment.
In still another embodiment of the user apparatus, a small gravity sensitive object hanging from a string attached to a central location is used. Around the central string attachment area are a series of targets. The hanging object is brought close to this series of targets by the user moving his head. Between these positions is identified a path giving the user a visual feedback regarding the head motion path he is to take from one position to the next.
In still another embodiment of the user apparatus, the user places a device upon his head in a desired manner. The device contains a small LED screen which is visible to the user. Gravity sensors and a small microprocessor are used. The microprocessor is programmed such that a visual feedback is shown on the small LED screen giving the patient visual information about the position of his head and how he is to move his head to complete the PCRP.
Different combinations of certain of these embodiments may be used as a user apparatus and as an assistant apparatus for the diagnosis and treatment of BPPV.